M 47 is an open star cluster located
in the constellation of Puppis. It was discovered by Giovanni Batista
Hodierma in 1654 and was re-discovered by Charles Messier in 1771.
The cluster is 78 thousand years
old and and contains 50 stars. It lies 1,600 light years away and
covers 30 arcsec in the sky, approximately the size of a full moon.
At a magnitude of 4.2, it is
visible to the naked eye under dark skies.